Hey guys while driving around today my r56 2009 mini cooper (non turbo) began shaking and illuminated the check engine light, the light then started blinking. With this I knew the engine was mis firing so I drove to the closest autozone to check out my spark plugs and coils. Coils looked good but the spark plugs no so much. Once I replace all plugs the miss firings continued. Does anyone have any recommendations for what I should do next. I dont want to take it to the dealership because they will overcharge me for something im sure is really simple and im just overlooking.

 

read the obd codes even if there is no check engine light.

do you hear any weird noises coming from the engine? what about your oil level?

 

Does anyone know what this line is for?

 

Yea before there was a low hissing sound. vacuum leak?

 

Transmission vent line. Looks good and goes nowhere.

 

Quick Google shows O2 sensor and thermostat. Might need a BMW specific code reader.

 

How would I know if the problem is from bad ignition coils? Even though they looked fine could this still be a possibility?

 

Ok, so I ruled out the possibility of one of the coils being bad by turning on the engine and unplugging the wiring to each coil and listening for RPM changes. I did this several times and with each try moving the ignition coils over to the next cylinder. I was able to determine that there is no spark on cylinder number 3 (?), the second from the right side of the engine bay. I then looked at the wiring socket that connects to this ignition coil it is slightly dirty but not by much more than any of the rest. How should I go about cleaning these connectors and could someone give me tips on next steps that I should take, I would be very thankful.

 

Today I was able to rule out the possibility that the problem was with the fuel injector and ignition wiring by taking out the fuel injectors and watching all of them spray into the air and also removing the spark plug and watching it spark outside of the engine. I decided to pick up a compression tester and test cylinder number 3, sadly the test showed that there was no compression at all for this cylinder but all others were within a normal range. After seeing these results I removed the valve cover and began to look for any noticeable damage and this is what I discovered. My question now is how should I proceed with replacing this part inside the red circle and whats you guy's general thoughts on how this could have happened.

 

I remember having gone through this once. The fact that roller came out and you have no compression only means the valve is bent.

You can try to insert it back but i have a feeling it will not be secured.

 

You may have dropped a valve seat. These engines are famous for dropping valve seats, and it's happened to me too.

Check out this link:

http://www.engineprofessional.com/TB/TB113017-1.pdf